Food Allergy, Food Enemy?

If you have a food allergy, you may feel that food is no longer your friend. But knowledge is power. Learn how you can identify your food sensitivity and spot your triggers, even when they appear in disguise.

Allergies vs. intolerances

One friend says he has a food sensitivity, another says she has a food allergy. What is the difference and what do they mean? If you or someone you care about has problems with certain types of food, there can be a lot to learn. Here are the basics to help you get started.

Food sensitivity is an umbrella term used to describe any adverse reaction to food that you might experience. This means adverse reactions such as hives, wheezing, or wanting to gag at the thought of brussel sprouts. "Food sensitivities" refers to both food allergies and food intolerances. So what is the difference between an allergy and an intolerance, you ask? The answer lies in the immune system.

A food allergy occurs when your immune system reacts to a certain food as though it were harmful and something to be fought off. The first time the person with a food allergy encounters their trigger (or allergen), their bodies invoke a defence mechanism and create antibodies (specialized proteins) called immunoglobulin E (IgE). When the allergen is next introduced, the body releases these IgE antibodies as well as other chemicals (histamine being one) to defend itself against the perceived threat – and thus an allergic reaction proceeds. The symptoms of the reaction can vary in degree of seriousness from hives and tingling in the mouth to wheezing to a life-threatening encounter with anaphylaxis, a severe form of allergic reaction.

Comfortingly, actual food allergies are relatively rare – in Canada, only 3% to 4% of adults and 6% of children live with these conditions. As the numbers indicate, children tend to outgrow allergies. However, there's no guarantee, especially if the allergy involves peanuts, shrimp, or fish. And unfortunately for adults, there's no moment at which you receive your free pass, as allergies can develop at any age.

Food intolerance is a bad reaction to food that does not involve the immune system. Its root often lies in the gastrointestinal system, and is related to an individual's inability to digest or absorb particular foods (or parts thereof). Because the immune system is not at work here, it generally takes a larger, more portion-sized amount of the problem food to trigger a reaction, as opposed to the tiny amount that is often enough to trigger an allergic response. Symptoms of food intolerance can include gas, bloating, vomiting, and diarrhea. A well-known type of food intolerance is lactose intolerance, which is an inability to digest lactose, the sugar in milk.

Food allergens: the usual suspects

Got a food allergy, or think you have one? Health Canada has identified nine food allergens, foods most commonly associated with allergic reactions. While you can develop a sensitivity to any food, just a small minority are involved with the majority of food allergies.

Without further ado, meet the usual suspects:

eggs

fish (includes crustaceans and shellfish)

milk

peanuts

sesame seeds

soy

sulphites (a food additive that is also naturally found in food and the body)

The foods listed above can produce a variety of allergic reactions that range from a mild case of hives to an extreme situation where you have trouble breathing. These foods can also be listed under other names in the ingredient list on a package. If you believe you have a food allergy, talk to your doctor. Don't take chances!

I have a problem with certain foods. What now?

If you think you have a food sensitivity, take heart and have patience. You may feel discouraged by a complex new world of food restrictions, but remember that it comes hand in hand with hope for better health!

It is very important to speak to your doctor about your food problems. He or she can discuss with you your symptoms, suspected triggers, and family medical history, and can perform a physical examination to rule other possible causes or illnesses. Your doctor may also refer you to an allergist, a doctor who specializes in allergies and disorders of the immune system. This process plays a key role in a possible eventual diagnosis of a food allergy or intolerance.

To assist in determining the nature of your food problem, your doctor may also ask you to do the following:

Log your food and medication intake and symptoms. This involves keeping tabs on what you eat and drink at mealtimes (and snack times) and writing it down in a food diary. You also need to mark down what medications you take and when you take them. Make sure to include notes on subsequent physical reactions. This can help you and your doctor connect the dots with an accurate, detailed overall picture. It's possible that medications may be playing a part with your symptoms too.

Follow an elimination diet. By removing suspected triggers from your diet for a short time (a week or two), you and your doctor can monitor your body's reaction once the foods are gradually reintroduced to your system. While this isn't a foolproof method of assessment, it can provide some insight. Naturally, for people with suspected severe allergies, deliberately ingesting the allergen is not a safe or wise option.

Have a skin test. To help identify your particular allergen(s), your doctor will lightly prick or scratch a few spots on your back or part of your arm with a needle, and then place a small, diluted quantity of the suspected allergen on the exposed area so that the substance can reach below the surface of the skin. If, after about 15 minutes, a small bump or redness appears, there's about a 50% chance that you are allergic to that substance. If no reaction occurs, you have about a 90% chance that you are not allergic to that substance.

Do a blood test. A blood sample taken at your doctor's office can be sent to the laboratory for further testing. Unfortunately, the findings from this type of test may not be conclusive, so make sure you discuss with your doctor how to best understand your results.

If you are diagnosed with a food allergy, there is as yet no magic cure to make it go away. The best management technique is to avoid your allergens altogether. This means you'll need to learn to identify and recognize your "enemy" so you can keep it out of your diet. And the flip side is that you'll need to learn and remember what foods you can eat!

For those with a severe allergy at risk of anaphylaxis (a life-threatening form of allergic response), your doctor may prescribe an injectable medication called epinephrine, also known under the brand names EpiPen® and Twinject®. You will need to carry this medication with you at all times, as you may not be able to predict or control your exposure to your allergen – and if you need it, you'll need it fast. Immediate injection after exposure to your allergen is crucial for those at risk of anaphylactic shock. If you have this medication, you may wish to educate your family, friends, and colleagues on how to administer it should the need arise and you are not able to give it to yourself.

For those with milder allergic responses, antihistamine pills (e.g., diphenhydramine, hydroxyzine, cetirizine) may help to control or reduce your allergic response.

Feeling daunted? Don't! Remember that working with your body to give it the food it wants and removing the food it doesn't will yield positive results for your health. Yes, you may need to change your diet, but keep sight of all the foods still available to you. You may even discover some new favourites!

Read the ingredients

What's wheat doing in my veggie patty? How did corn get in my cola? You may think you know what you're eating, but reading the ingredient label can reveal some surprises. Knowing what to look for helps too. If you have allergies, being able to navigate ingredient labels is critical. It may even safe your life.

Know your enemy. We have no cure for food allergies or intolerances, so avoiding your allergen is a key management technique. Many of us have the luxury of not needing to read the label or consider the ingredients of the food we eat. But living with a food allergy demands extra sleuthing. Some pitfalls are obvious and easy to identify, such as avoiding nut butters when you're allergic to nuts, but others require more detective work. For example, wheat can appear as an ingredient in imitation meat or seafood products, or it may turn up in ice cream. Soy could appear in your peanut butter, canned tuna or baby formula. Get into the habit of always checking ingredient labels. And remember, manufacturers may change their ingredients at any time, so don't lower your guard.

That food may be travelling under an assumed name. To add to the complexity, some ingredients and their products can take on different names, so they require more advanced detecting skills. Did you know that cornstarch is a popular sweetener used by food manufacturers? A few of its hiding places include salad dressings, frozen puddings, beverages, and canned fruit. If corn is not your friend, you'll need to be able to recognize it under its aliases such as dextrose, corn syrup, maltodextrin, and crystalline fructose. Similarly, peanut oil may use the name "arachis oil," or the term "artificial nuts" may include peanut products. Eggs might hide out under different names such as albumin or ovomucoid and pop up in places such as meatballs, foamed toppings in coffee, or baked goods.

Look for stowaways in your pantry. Finally, as if allergens didn't have disguises enough, sometimes ingredients can just sneak into the manufacturing process unannounced. To combat this, Health Canada, together with the Canadian Food Inspection Agency, publishes allergy alerts to inform Canadians about undeclared ingredients in processed food. Don't let allergens hide in your cupboard. Stay safe and keep checking the alerts at www.hc-sc.gc.ca.

Bottom line: If you or someone in your family has a food allergy, talk to your doctor about what foods to avoid and what foods to stay on the lookout for. Your doctor may also suggest you speak with a dietitian to ensure you still meet all your nutritional requirements despite having eliminated certain foods from your diet.